While voice communications systems carry the bulk of our casual messages, it remains the task of written communications to convey vital information between organizations. Written messages provide clarity of detail, serve as permanent records, and are readily sorted, prioritized, and routed.
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Message-handling systems allow the exchange of electronic mail between computers. The International Telegraph and Telephone Consultative Committee (CCITT) has proposed a standard for message-handling systems in the form of the X.400 series of recommendations that has been widely recognized by computer manufacturers and communications carriers. This paper provides a tutorial on the X.400 recommenda...
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This paper describes a novel technique for the specification and implementation of layered communication software. The technique is called Parallel Activity Specification Scheme (PASS) and is based on an extended-state machine model of protocol automata. It allows a convenient description of the communication behavior of concurrent systems and semiautomatic generation of programming language code ...
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With increasing size and complexity of the implementations of information systems, it is necessary to use some logical construct (or architecture) for defining and controlling the interfaces and the integration of all of the components of the system. This paper defines information systems architecture by creating a descriptive framework from disciplines quite independent of information systems, th...
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In recent years, there has been a growing requirement for continuous processing capability approaching 24 hours per day, 7 days per week. Industries such as finance, transportation, securities, and telecommunications have continuous-availability requirements that can approach downtimes of not more than three minutes per year. This paper describes configurations of the Stratus/32 continuous process...
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